Speaking at Barnes & Noble’s store in Manhattan’s Union Square, William Lynch, the company’s chief executive, set the new Nook directly up against Amazon’s recently released Kindle Fire, promoting what he described as the Nook’s advantages in memory and multimedia capability.

“The Kindle Fire, and they do a lot of things well, is a vending machine for Amazon services,” Mr. Lynch said. “We’re going to partner with the world’s most popular music services. We’re going to let the consumers choose.”

The new tablet, which is lighter and faster than other Nook devices, offers access to popular apps including Netflix, Hulu Plus and Pandora.

The unveiling of the new tablet set up what is sure to be a heated competition between Barnes & Noble, Amazon and Apple, maker of the iPad, for the quickly expanding group of consumers who will shop for color tablets this holiday season. Amazon’s Kindle Fire retails for $199 and will start shipping next Monday.

Barnes & Noble executives emphasized that its devices have no ads that interrupt the reading experience. That provides an advantage over other e-readers and tablets that do have advertising, said Michael Norris, a senior analyst with Simba Information, which provides research and advice to publishers.

“We’ve done research, and the ads are considered annoying, irritating and obtrusive,” Mr. Norris said after watching Barnes & Noble’s presentation.

Barnes & Noble also revealed an expanded display area for Nook devices in the back of its Union Square store.

“It’s the same kind of experience as Apple,” said Leonard Riggio, the chairman of Barnes & Noble, as he stood in the display area after the news conference. “It makes the product and category much more important.”